Deceitful Volcanic Secrets: Unveiling the ways volcanoes can mislead about their age, and the implications for humanity
In the heart of New Zealand's North Island lies Lake Taupo, a caldera volcano that experienced a violent eruption about 1,800 years ago, marking the most powerful eruption in the past 5,000 years. Recent research has shed light on the factors that may have contributed to this cataclysmic event, and potentially, the forecasting of future large eruptions.
A significant discovery has been made regarding the influence of volcanic carbon dioxide on eruption ages. The groundwater beneath the lake and its surroundings plays a crucial role, as a large and increasing volume of carbon dioxide gas containing stable isotopes was emitted from deep below the prehistoric Taupo volcano. This carbon dioxide was redistributed by the region's groundwater system and incorporated into the wood of dated trees.
The ratio of carbon-13 to carbon-12 in the modern water of Lake Taupo and the Waikato River indicates that volcanic carbon dioxide is getting into the groundwater from an underlying magma body. This anomalous chemistry mimics but exceeds the Suess effect, which reversed the carbon isotopic evolution of post-industrial wood.
Researchers have found that the oldest dates for the Taupo eruption were closest to the volcano vent, with dates progressively younger the further away they were. This unusual geographic pattern, with the oldest ages for the Taupo eruption being clustered around Lake Taupo and older ages located further from the volcano, suggests that contamination of samples with volcanic carbon dioxide may have occurred.
The increase in carbon dioxide gas over several decades dramatically altered the ratios of different carbon isotopes in the tree wood. The precursory change in carbon ratios provides a way to gain insight into the forecasting of future eruptions. The radiocarbon dates and isotope data reached a plateau, meaning that for several decades before the eruption, the outer growth rings of trees had weird carbon ratios, forecasting the impending eruption.
This research suggests that large eruptions may have effects on their surroundings that can be detected decades before the eruption occurs. Similar patterns were found in other major eruptions, including at Rabaul in Papua New Guinea and Baitoushan on the North Korean border with China.
The findings of this research are expected to provide a significant focus for future research at supervolcanoes around the globe. The anticipation is that this will lead to a better understanding of the precursors to large eruptions and potentially, the development of methods for forecasting such events.
However, more research is needed to confirm the exact mechanisms at play and to determine which peoples conduct volcanology research on the Taupo Caldera. The search results do not provide information about this aspect.
In conclusion, the study of the Taupo eruption has provided valuable insights into the role of volcanic carbon dioxide in the precursors to large eruptions. The findings suggest that large eruptions may have effects on their surroundings that can be detected decades before the eruption occurs, offering the possibility of forecasting future large eruptions.
